Practically everyone at one time or another has used a sled to slide down a hill on snow and remembers what fun it was. However, during the summer when hills are covered by grass or dirt or in climates that do not have snow, there is no “summer sled” or “grass sled” that can provide similar fun. Some prior devices have attempted to provide a board or ski with ground friction-reducing mechanisms for this purpose. As examples, U.S. Pat. No. 6,367,827 shows a slider board with side rails mounting a crawler track over a series of rollers in a line from front to back. U.S. Pat. No. 6,007,074 shows a boot-mounting skateboard fitted with an endless belt tracked around a pair of spaced apart rollers. U.S. Pat. No. 4,572,528 shows a grass ski with boot mounting and a slider belt entrained over a spring-loaded system below. U.S. Pat. No. 4,440,408 shows an elevated seat mounted on a ski board sliding on an endless belt supported on rollers. U.S. Pat. No. 6,209,894 shows a ground sled supported on parallel front-to-back wheel racks. U.S. Pat. No. 6,431,560 shows a sliding board which has clamps for holding blocks of ice on its lower surface to eliminate friction when used on the ground. Other devices have been proposed that provide variations of a tracking sled, ski, or skateboard powered with an endless belt driven by a motor.
However, these types of prior board or sled devices have required complicated and expensive bearings, mounting, and/or tracking systems which make them very costly to manufacture and difficult to maintain in fault-free, usable condition. The various types of “grass skis” or “grass skateboards” also have complicated systems of wheels, rollers, or belts. In addition, the presence of a wheeled, rollered, or tracked system beneath a slider board, ski, or skateboard elevates its height above the ground and risks possible injury to the user from tipping or flipping over. Standing up, sitting on a seat, or sitting or lying on an elevated board also does not give the user as keen a sense of being in contact with and sliding or “surfing” on the ground.